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Biomedical subjects

T Katayama

Publications and source records attributed to T Katayama.

At least 433 records · Page 24Linked to original sources
PubMed1987

Evidence for a defect in urinary concentrating ability in primary aldosteronism and its reversal by adrenal surgery.

Of 15 patients with primary aldosteronism, 7 had idiopathic adrenal hyperplasia (IHA) and 8 had aldosterone-producing adenoma (APA). In order to determine any renal problems involved in the treatment, the renal clearance of these patients was analyzed and the results compared with those obtained from 12 patients with essential hypertension. With water diuresis or under antidiuresis status, levels of urine volume, Cosm and CH2O in patients with APA were greater (p less than 0.05-p less than 0.001) than those of patients with essential hypertension, while the fractional tubular sodium delivery of the former patients was lower than that of the latter patients (p less than 0.001 or less than 0.05). A similar tendency was observed in clearance studies in patients with IHA, although to a lesser extent. Adrenal surgery for patients with APA normalized these values, but administration of trilostane (3 beta-hydrosteroid dehydrogenase inhibitor) to patients with IHA failed to improve these values. These results indicate that impaired urinary concentrating ability as well as reduced urinary diluting capability is a common feature of primary aldosteronism. Such impaired renal function was improved only in patients with APA after adrenal surgery.

Adenoma↗
PubMed1987

Use of indwelling double-curved ureteral stents and problems after stenting.

Indwelling double-curved ureteral stents were placed in 19 patients for 28 months. We used these stents to bypass ureteral obstruction and as adjunct surgery of upper urinary tract troubles. There were 5 cases with stent problems such as stone formation and spontaneous breakage. The duration of stenting with problems was longer than that without problems with statistical significance.

Adult↗
PubMed1987

Inhibition of superoxide anion production in guinea pig polymorphonuclear leukocytes by a seleno-organic compound, ebselen.

Production of superoxide anion (O2-) induced by tetradecanoyl phorbol acetate (TPA) in intact guinea pig polymorphonuclear leukocytes (PMNL) was markedly inhibited by a seleno-organic compound, 2-phenyl-1,2-benzisoselenazol-3(2H)-one (Ebselen), with glutathione peroxidase-like activity. The compound almost completely inhibited O2- production by a particulate fraction prepared from TPA-treated PMNL at a concentration as low as 250 nM.

Animals↗
PubMed1987

Effects of dietary xenobiotics on the metabolism of copper, alpha-tocopherol and cholesterol in rats.

The effects of dietary addition of some xenobiotics on tissue levels of copper and alpha-tocopherol in rats were studied with special reference to serum cholesterol. The chemicals added here were 0.05% polychlorinated biphenyls (PCB), 0.3% caffeine, 0.05% 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 0.3% flavone, 0.3% chloretone, 0.3% 2-tert-butyl-4-methoxyphenol (BHA), 0.15% sodium phenobarbital, 0.15% phenytoin, 0.2% sodium pentobarbital, and 0.15% phenylbutazone. Of these chemicals, dietary PCB, caffeine, DDT, flavone, chloretone, BHA and phenytoin raised the level of copper in liver, kidney, or serum. Serum alpha-tocopherol and cholesterol also increased with the additive or synergistic effects on these metabolisms. Moreover, these combined addition of dietary 0.02% PCB with 0.2% BHA seemed to cause additive or synergistic effects on these metabolism. Moreover, these chemicals raised serum ceruloplasmin activity. In general, serum copper, ceruloplasmin activity and alpha-tocopherol were correlated with serum cholesterol in these dietary manipulations.

Animals↗
PubMed1987

Chloropolysporins A, B and C, novel glycopeptide antibiotics from Faenia interjecta sp. nov. V. Comparative studies of the biological properties.

Chloropolysporins A, B and C, as well as derivatives prepared from this group and alpha- and beta-avoparcins by enzymatic and mild acid hydrolysis, were active against Gram-positive bacteria including clinically isolated methicillin-resistant Staphylococci (MIC 0.39-6.25 micrograms/ml) and anaerobic enterobacteria (MIC 0.10-1.56 micrograms/ml). Derhamnosyl and demannosyl derivatives from both groups of antibiotics showed stronger activities than the parent compounds. The MIC and MBC values against Staphylococci were similar and were not effected by the presence of serum. Moreover, chloropolysporin C exhibited very strong synergistic effects with various beta-lactam antibiotics against methicillin-resistant strains of Staphylococcus aureus. Some of these compounds also protected mice from experimental infection with S. aureus. Acute toxicities of chloropolysporin by intravenous administration ranged from 215-290 mg/kg in mice. Chloropolysporin B as well as other glycopeptide antibiotics, showed distinctive growth promoting activity in broiler chickens.

Anti-Bacterial Agents↗
PubMed1987

[Renal cell carcinoma incidentally found by computed tomography: report of 4 cases].

A clinical study was made on 26 patients with renal cell carcinoma, who visited our department between October, 1979 and April, 1984. There were 21 men and 5 women. As the major initial symptoms, hematuria and flank pain were observed in 14 cases (53.8%), followed by symptoms of metastatic tumors in 7 cases (26.9%). Four cases of malignant renal masses which showed no abnormality on the excretory urogram were diagnosed by chance at the time of examination of the abdominal computed tomography (CT). CT was especially useful in diagnosing the renal cell carcinomas.

Adult↗
PubMed1986

Hydrolysis of neo-kyotorphin (Thr-Ser-Lys-Tyr-Arg) and [Met]enkephalin-Arg6-Phe7 by angiotensin-converting enzyme from monkey brain.

Angiotensin-converting enzyme (ACE; dipeptidyl carboxypeptidase, EC 3.4.15.1) from monkey brain was partially purified 274-fold with 4.5% yield. The optimum pH of the enzyme was 8.2, and its Km was 3.3 mM, with hippuryl-His-Leu as the substrate in 300 mM NaCl. Its molecular weight (Mr) was estimated to be approximately 260,000 by gel filtration on Sephadex G-200. On high-performance liquid chromatographic analysis, ACE hydrolyzed neo-kyotorphin Thr-Ser-Lys-Tyr-Arg) with liberation of kyotorphin (Tyr-Arg), the [Met]enkephalin releaser. ACE also converted [Met]enkephalin-Arg6-Phe7 to [Met]enkephalin; then the enzyme slowly hydrolyzed the resulting [Met]enkephalin. The Km values of the enzyme for neo-kyotorphin and [Met]enkephalin-Arg6-Phe7 were 0.58 and 0.30 mM respectively. Thus, brain ACE may have a role in the formation of kyotorphin and [Met]enkephalin from their precursors but has little part in [Met]enkephalin degrading processes.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1986

Microdosimetric considerations of effects of heavy ions on microorganisms.

An estimation of dose around the trajectory of an ion has been made by use of Tabata and Ito's energy deposition algorithm for electrons which takes into account transmission coefficient. The result of the calculation, as well as Butts and Katz's dose, is successfully applied to the interpretation of inactivation cross sections of vegetative cells of E. coli Bs-1, and E. coli B/r and of B. subtilis spores for He, C and N ions.

Algorithms↗
PubMed1986

Participation of central norepinephrine in the development of two-kidney, one clip Goldblatt hypertension.

Two series of experiments were conducted to ascertain whether the central catecholamines would participate in the elevation of blood pressure in two-kidney, one clip (2K-1C) Goldblatt hypertensive rats. The effect of 6-hydroxydopamine (6-OHDA) injected intraventricularly (250 micrograms/kg.) before the induction of hypertension (acute phase) or after the establishment of hypertension (chronic phase) was examined in 2K-1C rats and sham rats. The evidence has been presented: 1) that the hypothalamic norepinephrine content of 2K-1C rats in acute phase is 50 per cent lower (p less than 0.001) than that of sham rats, but norepinephrine content in the pons is similar in these animals, 2) that the content of dopamine in hypothalamus or pons is similar in 2K-1C rats and normotensive age-matched sham rats in acute phase, 3) that the content of these monoamines either in hypothalamus or pons in 2K-1C rats in chronic phase is almost identical with that in sham rats, 4) that administration of 6-OHDA markedly reduced the development of hypertension in 2K-1C rats in the acute phase, but did not affect their sustained hypertension in the chronic phase. These findings suggest that hypothalamic norepinephrine participates in the development of hypertension in 2K-1C rats in the acute phase but is not connected with the maintenance of their established hypertension in the chronic phase.

Animals↗